U.S. patent number 4,660,259 [Application Number 06/891,945] was granted by the patent office on 1987-04-28 for twist resistant reclosable extruded plastic fastener.
This patent grant is currently assigned to Minigrip, Inc.. Invention is credited to Steven Ausnit.
United States Patent |
4,660,259 |
Ausnit |
April 28, 1987 |
Twist resistant reclosable extruded plastic fastener
Abstract
An extruded plastic reclosable fastener strip has a base from
which extends a stem and a resiliently flexible, foldable hook
flange projecting in normal position obliquely from the distal end
of the stem toward, but spaced from, a stiff backup shoulder rib
extending from the base in the same direction as, and substantially
spaced from, the stem. The rib is about the same length as the
stem, and the spacing between the rib and the stem provides a
groove socket of ample dimensions relative to the foldable hook
flange and the stem so that in a fastener closing maneuver a hook
flange and a stem of a complementary profile of a companion
fastener strip can be received in assembly slidably between the rib
and the foldable hook flange by folding of the foldable hook flange
substantially completely toward the stem until the hook flanges
pass one another and the foldable hook flange then snaps back to
the oblique position for interlocking with the profile hook flange
of the companion fastener strip in a manner to resist separation of
the interlocked strips due to twisting distortions.
Inventors: |
Ausnit; Steven (New York City,
NY) |
Assignee: |
Minigrip, Inc. (Orangeburg,
NY)
|
Family
ID: |
25399092 |
Appl.
No.: |
06/891,945 |
Filed: |
August 1, 1986 |
Current U.S.
Class: |
24/585.12;
24/704.1; 24/DIG.39; 24/DIG.50; 383/64 |
Current CPC
Class: |
B65D
33/2541 (20130101); A44B 19/16 (20130101); A44D
2200/12 (20130101); Y10T 24/50 (20150115); Y10S
24/39 (20130101); Y10T 24/45168 (20150115); Y10S
24/50 (20130101) |
Current International
Class: |
A44B
19/16 (20060101); A44B 19/10 (20060101); B65D
33/25 (20060101); A44B 019/00 (); B65D
033/24 () |
Field of
Search: |
;24/587,576,578,704
;383/63,64,35 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sakran; Victor N.
Claims
I claim as my invention:
1. An extruded plastic fastener strip adapted for reclosable
cooperation with a complementary fastener strip, and
comprising:
a base from which extends a stem and a resiliently flexible,
foldable hook flange projecting in normal position obliquely from
the distal end of the stem toward a stiff backup shoulder rib
extending from the base in the same direction as and substantially
spaced from said stem;
said hook flange being of greater length than the thickness of said
stem and being resiliently flexible for folding substantially
completely toward the stem; and
said rib being about the same length as the stem and the spacing
between the rib and the stem providing a groove providing a socket
of ample dimensions both in width and depth relative to the
foldable hook flange and the stem so that in a fastener closing
maneuver a hook flange and stem of a complementary profile of a
companion fastener strip can be received slidably between the rib
and the foldable hook flange by said folding of the foldable hook
flange toward the stem until the hook flanges pass one another and
the foldable hook flange then snaps freely back toward the normal
oblique position for interlocking with the profile hook flange of
the companion fastener strip.
2. A fastener strip according to claim 1, wherein said hook flange
has an inner substantially straight surface which meets the
adjacent surface of said stem at an acute angle so that said
surfaces can lie close to one another when the hook flange is
folded toward the stem.
3. A fastener strip according to claim 1, wherein said stem is of
substantially uniform thickness throughout the major extent of its
length.
4. A fastener strip according to claim 3, including a thickened
reinforcing juncture of said stem with said base.
5. A fastener strip according to claim 1, wherein said hook flange
joins the stem at a thickened juncture crown.
6. A fastener strip according to claim 1, wherein said backup
shoulder rib has a stiffening reinforcement juncture with said
base.
7. A fastener strip according to claim 6, wherein said stiffening
reinforcement juncture comprises a fillet.
8. A fastener strip according to claim 6, wherein said stiffening
reinforcement juncture includes a base extension and a fillet at
juncture of the rib and the extension.
9. A fastener strip according to claim 1, wherein both said stem
and said rib have reinforcing juncture fillets with said base.
10. An extruded plastic reclosable fastener assembly comprising a
pair of complementary fastener strips, each of which
a base from which extends a stem and a resiliently flexible,
foldable hook flange projecting in normal position obliquely from
the distal end of the stem toward a stiff backup shoulder rib
extending from the base in the same direction as and substantially
spaced from said stem;
said hook flanges being of greater length than the thickness of
said stem in each instance and being resiliently flexible for
folding substantially completely toward the stems; and
said ribs being about the same length as the stem of each strip and
the spacing between the rib and the stem of each strip providing a
groove forming a socket of ample dimensions both in width and depth
relative to the foldable hook flange and the stem, so that in a
fastener closing maneuver the hook flange and stem of each of the
complementary profiles of the fastener strips can be received
slidably between the rib and the hook flange of the other strip by
said folding of the foldable hook flanges toward the stem of the
associated strip until the hook flanges pass one another and the
foldable hook flanges then snap freely past one another back toward
their normal oblique positions for interlocking of the hook flanges
against separation due to bending stresses on the assembly.
11. A fastener assembly according to claim 10, wherein each of said
hook flanges has an inner substantially straight surface which
meets the adjacent surface of the stem from which the hook flange
projects at an acute angle so that said surfaces can lie close to
one another when the hook flange is folded toward the stem.
12. A fastener assembly according to claim 10, wherein each of said
stems is of substantially uniform thickness throughout the major
extent of its length.
13. A fastener assembly according to claim 12, including a
thickened juncture of each of said stems with the respective base
from which the stem projects.
14. A fastener assembly according to claim 10, wherein said hook
flanges join the stems on respective thickened juncture crowns.
15. A fastener assembly according to claim 10, wherein said backup
shoulder ribs have respective stiffening reinforcement junctures
with said base.
16. A fastener assembly according to claim 15, wherein said
stiffening reinforcement junctures comprise fillets.
17. A fastener assembly according to claim 15, wherein each of said
stiffening reinforcement junctures includes a base extension and a
fillet at juncture of the associated rib and extension.
18. A fastener assembly according to claim 10, wherein said stem
and said rib have reinforcing juncture fillets with said bases.
19. An extruded plastic reclosable fastener assembly comprising a
pair of complementary fastener strips, each of which comprises:
a base from which extends a stem and a resiliently flexible,
foldable hook flange projecting in normal position obliquely from
the distal end of the stem toward a stiff backup shoulder rib
extending from the base in the same direction as and substantially
spaced from said stem;
said hook flanges being of greater length than the thickness of
said stem in each instance and being resiliently flexible for
folding substantially completely toward the stems; and
said ribs being about the same length as the stem of each strip and
the spacing between the rib and the stem of each strip providing a
groove forming a socket which is of a width which is the sum of the
thicknesses of said stems and the space between the inside faces of
the stems and of ample depth relative to the foldable hook flange
and the stem, so that in a fastener closing maneuver the hook
flange and stem of each of the complementary profiles of the
fastener strips can be received slidably between the rib and the
hook flange of the other strip by said folding of the foldable hook
flanges toward the stem of the associated strip until the hook
flanges pass one another and the foldable hook flanges then snap
freely past one another back toward their normal oblique positions
for interlocking of the hook flanges against separation due to
bending stresses on the assembly.
20. An assembly according to claim 19, wherein said hook flanges
join their respective stems at a relatively thick crown, which has
a radius of curvature which about equals the thickness of the stem,
the length of the stem from the top of said crown to the level of
the inside surface at the bottom of the socket comprising the sum
of about two times the length of the hook flange in each instance
taken in a straight line between a free tip and the top point of
the radius of curvature of said crown plus one-half of the
thickness of the stem, the thickness of said base being about the
thickness of the stem plus 20%, the length of the inside surface of
each of the hook flanges being about the same as the spacing
dimension between the inside surfaces of said stems in the assembly
or about two times the thickness dimension of the stems, said
outside length of the hook flange being about the sum of the length
of the inside surface of the hook flange plus the radius of
curvature of said crown, the thickness of each of said ribs being
about the same as the outside length of the hook flanges, said
length of the stems being about two times the outside length of the
hook flange plus one-half of the stem thickness, and the thickness
across the base of the hook flange being about twice the thickness
of the tip end of the hook flange.
Description
BACKGROUND OF THE INVENTION
This invention relates to reclosable extruded plastic fasteners of
the kind having interlockably cooperative fastener strips which are
suitable for convenient manipulation into closed and open modes,
and according to the present invention will thoroughly resist
unintended opening due to twisting of the fastener assembly.
Heretofore, extruded plastic reclosable fasteners having
complementary interlockable hook profiles have been successfully
developed for wide ranging market utility.
One popular form of such reclosable fasteners has been the type
wherein an essentially arrow-shaped profile is interlockably
engagable in a complementary groove-shaped profile. While numerous
patents disclosing this type of fastener could be listed, U.S. Pat.
No. 3,808,649 has been selected as representative. While, in
general, this type of fastener is of the readily manipulatable type
for opening and closing, U.S. Pat. No. 3,808,649 combines the
readily closing manipulation feature with permanent closure
requiring either destruction or assistance of a tool for opening
the fastener.
Extruded plastic fasteners of the kind to which the present
invention is especially directed are represented in U.S. Pat. Nos.
3,633,642 and 3,886,633, wherein complementary fastener strips have
monohook profiles which snap together and are held against
unintentional displacement by backup flanges. In the fasteners
disclosed by these patents, the interlocking hooks are relatively
short and have reinforced fairly massive crown structure so that
due to the relatively stiff action of the hooks, the backup flange
structure as well as the profile stems must flex substantially both
when snapping the fastener strips together and when separating the
fastener strips.
A problem that has been encountered with respect to fasteners of
especially the form shown in U.S. Pat. No. 3,633,642 resides in
that under twisting conditions, the hook profiles of the fasteners
may tend to release, and the fastener thus be unintentionally
opened. It is to the alleviation of this problem that the present
invention has been devised.
SUMMARY OF THE PRESENT INVENTION
An important object of the present invention is to provide an
extruded plastic fastener strip construction wherein cooperating
monohooks are especially constructed and arranged for cooperative
resistance to release due to twisting of the fastener assembly in
which the strip is incorporated.
Another object of the invention is to provide a new and improved
extruded plastic fastener construction which will thoroughly resist
opening by twisting of the fastener, but which can be readily
manipulated for closing and opening as desired.
Pursuant to the present invention, there is provided an extruded
plastic fastener strip adapted for reclosable cooperation with a
complementary fastener strip, and comprising a base from which
extends a profile including a stem and a resiliently flexible,
foldable hook flange projecting in normal position obliquely from
the distal end of the stem toward, but spaced from, a stiff backup
shoulder rib extending from the base in the same direction and
substantially spaced from the stem, the rib being about the same
length as the stem and the spacing between the rib and the stem
providing a groove of ample dimensions relative to the foldable
hook flange and the stem so that in a fastener closing maneuver a
hook flange and stem of a complementary profile of a companion
fastener strip can be received slidably between the rib and the
foldable hook flange by folding of the foldable hook flange toward
the stem until the hook flanges pass one another and the foldable
hook flange then snaps back to the oblique position for
interlocking with the profile hook flange of the companion fastener
strip.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will be
readily apparent from the following description of a representative
embodiment thereof, taken in conjunction with the accompanying
drawing, although variations and modifications may be effected
without departing from the spirit and scope of the novel concepts
embodied in the disclosure, and in which:
FIG. 1 is a representative cross sectional detail view of a
monohook fastener structure according to the present invention;
FIG. 2 is a view similar to FIG. 1, but showing the monohook
profiles at the beginning of a fastener closing operation;
FIG. 3 is a view similar to FIG. 2, but showing the elements after
the closing maneuver has progressed part way; and
FIG. 4 is an illustrative view similar to FIG. 1, demonstrating the
action of the foldable hook flanges of the cooperating fastener
profiles.
DETAILED DESCRIPTION
A fastener assembly as shown in the drawings comprises cooperating
extruded plastic fastener strips 10 which may be attached to
respective sheets or panels 11 to be secured in a readily
reclosable manner. It will be obvious that the disclosed fastener
(also sometimes referred to as a zipper) may be extruded in various
sizes, proportionate to the particular uses to which put, such as
for sheet connection purposes as in tarpaulins, field covers,
tapestry and drapery hangings, top closures for containers such as
bags and sacks, and the like. In any such uses, the fastener
assembly may be subjected to twisting stresses which the fastener
strips 10 of the present invention are especially constructed to
resist and avoid unintentional opening of the fastener assembly.
Although as shown, the fastener strips 10 are extrusions formed
separately from the panels 11, and attached thereto as by means of
fusion welding or adhesive means, it is obvious that where
practicable the fastener strips may be extruded integrally with the
panels 11. Either of those alternative techniques are well known in
this art.
In the preferred example disclosed, each of the fastener strips 10
is identical in construction so that the strips can be extruded
from a single die in a continuous strip which can then be cut into
sections of whatever desired length and merely by reversing one
strip section relative to the other will be placed in reclosable
relation. Alternately several fastener strips can be extruded at
one time from one or more dies. Each of the strips 10 comprises a
base 12 from which extends a stem 14. A resiliently flexible,
foldable hook flange 15 projects obliquely from the distal end of
the stem 14 toward, but spaced from, a stiff backup shoulder rib 17
which extends from the base 12 in the same direction as and
substantially spaced from the stem 14. The rib 17 is about the same
length as the stem 14, but may be slightly longer, as shown, to
afford a greater backup length for the cooperating fastener stem
14. The spacing between the rib 17 and the stem 14 provides a
socket groove 18 of ample dimensions relative to the hook flange 15
and the stem 14, so that in a fastener closing maneuver, the hook
flange 15 and stem 14 of a complementary profile of a companion
fastener strip can be received slidably between the rib 17 and the
foldable hook flange 15 by folding of the foldable hook flange 15
toward the stem 14 until the hook flanges pass one another and the
foldable hook flange 15 snaps back to the oblique position for
interlocking with the profile hook flange of the companion
strip.
For optimum results, the several elements of each of the fastener
strips 10 are relatively constructed and proportioned in a
preferred manner having regard to various respective dimensions, as
will be explained for illustrative convenience by reference to
lower case lettered dimensional parameters which apply to each of
the strips 10 with equal effect.
Thickness dimension a of the stem 14 is measured between preferably
parallel respectively inside and outside faces 19 and 20 of the
stem, and the thickness is substantially uniform throughout the
major extent of the length of the stem.
Dimension b relates to the space between the confronting inside
faces 19 of the companion strips 10 in the closed fastener
assembled relation of the strips.
Dimension c is the sum of dimensions a and b and represents the
width of the socket 18.
A relatively thick crown 21 from which the foldable hook flange 15
extends has a curvate crown surface 22, a radius of curvature
dimension d which is desirably about the same as the stem thickness
dimension a. It may be pointed out that by preference the dimension
b is about two times the dimension d, or a. Stated another way, the
dimension b is about the sum of a and d.
The dimension e represents the length of the stem 14 from the top
of the crown 21 to the level of the inside surface of the base
12.
Dimension f is the outside length of the hook flange 15 taken in a
straight line between free tip 23 of the hook flange and the top
point of curvilinear crown surface 22. Note that the dimension e is
about 2f plus 1/2a.
Dimension g represents the thickness of the base 12 and desirably
is about the thickness of the stem a plus 20%.
Dimension h is the length of the inside surface of the hook flange
15, and is desirably about the same as the spacing dimension b, or
about two times the thickness of dimension a. The dimension f is
about the sum of the dimensions h and d.
Dimension i is the thickness of the rib 17 and is desirably about
the same as the dimension f. It may also be pointed out that, as
shown, the dimension e is desirably two times f plus 1/2 of a.
Dimension j across the thickness of the base of the hook flange 15
is preferably twice the thickness of the tip end toward which the
tapering surfaces of the hook flange 15 converge.
A few additional desirable structural features of the fastener
strips 10 may also be observed, including a width extension 24 of
the base 12 beyond the outer side of the rib 17. This extension 24
meets the outside base surface of the rib 17 on a fillet 25 and
provides, in effect, a bracing reinforcement which assists in
stiffening the rib 17 against undesirable outward deflection. A
fillet 27 at the inside juncture of the rib 17 with the base 12
serves the same function and cooperates with the fillet 25 in
resisting torsional or twisting deflections of the rib. A
chamferred or rounded leadin surface 28 at the top inner side of
the crown of the rib 17 facilitates assembly of the companion strip
profile into the socket 18, in cooperation with the transversely
curvilinear crown 22. A flat inner surface 29 of the rib 17
provides a broad wide surface slidably engagable in backup relation
with the surface 20 of the companion fastener strip profile stem
14.
For resilience and folding efficiency, the hook flange 15 is of a
generally tapered construction of about twice the thickness at
juncture with the crown 21, as compared to the thickness of the tip
23 which is desirably of a blunt truncated form. Preferably
straight inner surface 30 of the hook flange 15 desirably joins the
inner surface 19 of the associated stem 14 at a relatively accute
angle juncture 31. Thereby, the hook flange 15 is adapted to fold
closely toward the stem surface 19 with the hook flange surface 30
substantially parallel thereto.
At its juncture with the base 12, the stem 14 is desirably
substantially thickened as indicated at 32, whereby to further
improve resistance to twisting of the strip 10.
As shown in FIG. 2, when the strips 10 are brought into
registration for interlocking, the crown ends of the profile stems
14 enter into the outer ends of the sockets 18 and shoulder against
the outer end portions of the rib surfaces 29, with the outwardly
facing surfaces of the hook flanges 15 nested against one another
in a camming relation. Upon application of relative assembly
pressure, as indicated by the arrows 33, toward the fastener strips
10, the profile stem surfaces 20 will slidably advance inwardly as
backed up against the rib surfaces 29. The cammingly engaged hook
flanges 15 will deflect one another, as indicated by directional
arrows 34, toward the stem surfaces 19 of the companion strip in
each instance.
Continuing relative assembly movement of the fastener strips, as
indicated by the arrows 35 in FIG. 3, causes the hook flanges 15 to
foldably deflect one another toward the respective stems 14. Then
continuing assembly force causes the deflected, folded hook flanges
to pass one another until, as indicated by directional arrows 37 in
FIG. 4, the tips 23 of the pull flanges 15 clear one another and
the pull flanges snap into the normal oblique position for
interhooking of the hook flanges. The sockets 18 are of sufficient
depths to provide clearance for passing of the hook flanges 15
inwardly past one another into the expanded interhooked
relation.
It will be noted in FIGS. 1 and 4, that by the relatively sharply
angular oblique positions of the hook flanges 15, and the
relatively large confronting areas of the surfaces 30 of the hook
flanges, as well as the solid backup provided by the ribs 17 for
the stems 14 adjacent to which the tips 23 of the hook flanges are
located in the assembly, separation, that is opening, of the
fastener assembly is thoroughly resisted when the assembly is
subjected to twisting strains. Nevertheless, there can be adequate
resilient yielding of the components of the assembly when a
suitable separating mechanism is applied.
Although for illustrative purposes a single stem/foldable
flange/rib profile arrangement has been shown for each of the
cooperating fastener strips 10, it will be clear that multiples of
as many as desired of the stem/foldable flange/rib arrangements may
be provided on each strip to meet various practical
requirements.
It will be understood that variations and modifications may be
effected without departing from the spirit and scope of the novel
concepts of the present invention.
* * * * *